前言七○砂是1970年9月由我厂首创成功的一种新型铸造材料,是在伟大的无产阶级文化大革命中出现的新生事物,是贯彻落实“鞍钢宪法”所取得的显著成果,这是毛主席革命路线在铸造生产方面的重大胜利。七○砂从设想到正式转入试验、生产以来,由于它所独具的优 Preface VII. Sand is a new type of casting material successfully invented by our factory in September 1970. It is a new thing that emerged during the great Great Proletarian Cultural Revolution. It is a remarkable achievement in implementing the “Anshan Iron and Steel Constitution” Chairman Mao’s revolutionary victory in casting production. Seven sand from the idea to formally transferred to the test, since the production, due to its unique advantages